Unkillable
by Chessmaster10
Summary: Teachers are meant to be our second parents. They guide us, teach us, and nurture us as we go through our life in school and make our way into the world. But what is Class A to do when their task is to kill their super-powered octopus teacher with a deadline, before he destroys the Earth? Problem: he's the best teacher ever! Cover photo belongs to Yakushi-Kabuto on Deviantart.
1. Introduction Time!

**Ever since I watched Ansatsu Kyoushitsu, this idea has been stuck in my mind for a while. But since this is my first story on this website, I'm not expecting many reviews or anything of the like 'cause I'm a newb XP. I only read fanfiction up until this point, but seeing one crossover with this premise which was titled _Assassination Shinobi by PainX65_ inspired me to finally write one. So please enjoy! ^-^**

 **Critiques and comments will be appreciated.**

 **Also cover art isn't mine. It belongs to Yakushi-Kabuto on Deviantart, you guys should check his work, they're pretty good! :)**

 **URL cause I can't paste it on my profile for some reason XP:** **art/Assasination-Ninja-532329773**

 **Disclaimer: I do not own Naruto or Ansatsu Kyoushitsu. If I did, I wouldn't be here writing fanfics but be making sequels and spin-offs to the manga. XP**

* * *

Uniqueness was often something to be embraced wholeheartedly, sometimes even be admired. It made you who you were and defined you as a person through your words and actions.

What the class of aspiring shinobi-to-be of Konohagakure no Sato saw standing in front of their classroom was definitely unique. And completely, scientifically, logically and realistically impossible.

"Hello everyone, I was the one who destroyed Sora no Kuni," the creature in-front of the grinned, its small beady eyes giving them a sharp glance from where it stood tall and yellow behind the teacher's desk. "I plan to do the same to the Earth in a few years."

"But until then, I will be your teacher. I hope we can work well together." The creature's smile seemed to reach all the way until its eyes.

The class's eyes widened in unison. They knew of Sora no Kuni from their history lessons, its Hidden Village had been destroyed by Konoha during the Second Great Shinobi War as a a counter to its challenge to the Shinobi Godaikoku. The village itself had been left in ashes in Konoha's wake, but the country itself survived the aftermath... at least until most recently. The news had spread like wildfire throughout the Elemental Nations. Sora no Kuni; an already ruined nation reduced to ruble and nothing but 1.22 million miles of a giant crater had been left of it.

They had heard from their parents that through the rumor-mill, that only one single person was responsible for the unprecedented damage done to one entire nation and wiped it off the map indefinitely, left in the shape of a crescent moon.

The class sweat dropped in unison. What stood in-front of them looked nothing like what they had pictured a powerful super being would look like. Not even close by a long-shot.

It strangely held the appearance of a yellow bi-pedal octopus with four tentacles for arms, two of which had the strange appearance as if he had two long fingers on them. He stood at a tall 9.8'' with a large bulbous head with an absurdly large smile and small, beady eyes. He wore a black academic dress with a small black square academic cap with a yellow tassel hanging from the front, and a large black tie with a yellow crescent moon stitched onto it.

"Alright look..." the class looked toward the adult in the room, a Chunin by the looks of it, who smiled at them. "My name is Umino Iruka and let me get straight to the point."

"All of you in this classroom have been tasked by Hokage-sama with this emergency S-ranked mission." The scar-nosed Chunin then suddenly pinched the bridge of his nose. He then shot them all a serious gaze. "Let me be blunt: We want you to kill this creature."

The class went silent. And then exploded.

"NANI?!"

A student shot up from her seat. "How do you expect us to kill that bakemono?! We're just Academy Students!"

The creature gained a tick mark. "How rude! I'm right here you know?!"

"Asami-san, Bakemono-san; no need to point out the obvious. We're not blind you know. Maybe you both should get your eyes checked," A male student interrupted/drawled. A couple of students snickered.

"HEY!"

Iruka coughed into his fist to gain everyone's attention back. Everyone looked at him.

"Anyway..." he continued. "I'm afraid most of the details about this mission have been classified as an S-ranked secret and I'm not privy to them. However, according to Hokage-sama, he's telling the truth and he won't stop with just Sora no Kuni. He will destroy the Earth."

Multiple students simultaneously gulped.

"Only Hokage-sama and a select few are in the know; including the other Kage. There would be mass panic if word got out about someone existing with the power to bring down entire nations." The Chunin elaborated. "That is why _you_ have been tasked to kill him."

 _'Eh...?'_

A student raised his hand. "Ano, Iruka-san... wouldn't it be better if every shinobi were to know about him? Everyone would be out to kill him then; and he wouldn't be able to evade them forever."

"Nurufufu..." the creature laughed. "They tried. They sent 30 shinobi each from their ANBU squads and Elite Jonin. None of them even scratched me."

 _'NANI?!'_

Iruka sighed again. "This thing has the ability to go past the speed of sound-"

"Mach 20, to be precise Iruka-san." the bipedal octopus jovially interrupted. "That is approximately 24.8 kilometers per hour, faster than your average shinobi can track _and_ move."

The scar-nosed chunin's temple throbbed. "-according to the reports. And he can...fly..."

 _'...'_ The entire class's minds came to an abrupt halt. And then exploded.

 _'How on Earth are we suppose to kill that thing?!'_

"He's also immune to our more traditional weapons like shuriken and kunai." The Chunin informed them. "Even Jutsu have no effect on him..."

That raised a question in many of their minds.

"Iruka-san, how are you able to confirm all this if he evaded all our attacks?" A student asked the unvoiced question.

"He didn't." Was the blank response they received.

"Eh?"

"He stood still the entire time they attacked him..."

The class became abruptly silent.

"NANI?!"

"Nurufufu..." the super-octopus laughed, green lines appearing on his face. "I even gave their weapons maintenance checks during the fight."

Again, the class was silent.

"NANI?!"

Iruka pinched the bridge of his scar-marked nose. _'This is getting annoying...'_

"In short, if he wanted to get away from us, we wouldn't be able to do a thing to stop him." It was true. While Jutsu were very versatile and deadly, one thing that many jutsu shared as a weakness was their inevitably short range capacity. And they had seen this thing fly all the way up the stratosphere...

"Nurufufu..." The octopus laughed again. "But where would the fun in that be? So I made your village an offer. They will stop attempts on my life, and in return, I will teach here at the Academy."

Multiple sweat-drops formed on the student's head. Even Iruka seemed to have developed a tick mark.

 _'What...?Why...?/Did we get the short end of the stick...?'_ was the common thought that ran amuck the minds of multiple individuals in the room, complete with a baseball bat and guns blazing.

"We don't know what he's after..." Iruka breathed out, obviously quickly growing impatient every second. "But we really had no choice but to agree, on the condition that he doesn't harm any of you kids. We have two reasons for this: First and foremost, if he comes here everyday to teach, it will become easier to keep track of him. And secondly... it will give some thirty individuals a chance to kill him from extremely close range."

"Why are you making that thing our teacher?!"

"Why are you making us do your work? We're not even out of the Academy yet!"

The cries of protest grew louder and louder, and were suddenly silenced as Iruka finally blew his top.

"Because it's your job and responsibility to follow the Hokage's commands as shinobi-in-training!" Iruka shouted, his temper finally worn thin. His head enlarged to dramatic proportions, face as red as a tomato. "We could be putting these shinobi who serve as your teachers out on duty and missions right now, if they weren't ordered to teach you! Well, it's time to grow up and do your part as a Konoha shinobi!"

Iruke inhaled and exhaled to calm himself before he went any further, his head shrinking back to its regular size and color.

"Furthermore, the student who successfully manages to kill him will be awarded seventeen-billion ryo."

 _'Nani?!'_ the class's minds once again came to a screeching halt.

"It's only fair," Iruka shrugged. "If you can kill him, you will have literally saved the Earth. Fortunately, he doesn't seem to think much of you."

 _'How is that fortunate...?'_ was the bleak thought in their minds.

The Chunin motioned at the bipedal octopus. "See? Those green stripes on his face means he's looking down on you."

True to his words, their soon-to-be teacher did have three green stripes going horizontally across his smiling visage.

 _'Just what kind of skin is that?!'_ The class internally screamed.

"Nurufufu..." the yellow octopus laughed again. "Of course I am. If the elite forces of nearly every village couldn't kill me, then how could you?"

His smile seemed to get bigger. "They even hired a few S-ranked missing-nin to off me. All they got was a good make-over mid-fight!"

 _'What's up with the cleanliness...?'_

Iruka coughed to gain their attention again. "While he's busy looking down on you, your job is to find a hole in his defenses and strike from there. We'll provide you with weapons that won't hurt you, but will hurt him."

At that point, two shinobi came in, wheeling a trolley filled with what looked like green kunai and shuriken. The two unnamed shinobi, took some from the trolley and handed them out to the students.

One student poked the tip and his eyes widened. He pulled down on the green blade, and it bent like rubber.

"H-Hey!" he stood up, clearly irritated. "You really expect us to kill him with weapons like these?!" To emphasis his point, he bent the rubber blade once more.

"Yeah," another student droned out. He threw one of the shuriken at the wall and the weapon merely bounced off the wall, not even leaving a scratch upon the wood. "How are these suppose to harm him? They're practically toys. You sure you guys are alright in the head?"

Iruka sighed out in obvious irritation and mental exhaustion. "They might not seem like much, but they do work."

Another student raised her hand. "Did Konoha make these weapons?" she asked.

"No," Iruka replied. "These were given to us by Oto no Kuni,"

Despite all the questions that were raised in their minds by the statement, the students reluctantly nodded, and pocketed the weapons in their weapon pouches.

The chunin then gave them a serious look. "I suppose that the specifics of this being an S-ranked secret do not need to elaborated on?" Taking in their nods, he continued.

"There's no time to lose." Iruka lingered. "Well, that's about the gist of it. I hope you'll make the most of your last few remaining years."

The chunin then smiled at them. "Good luck!"

The students merely gave deadpanned looks at the chunin. The scar-nosed chunin at least had the the decency to look sheepish.

The octopus suddenly rubbed his hands- tentacles? together, as if giddy with anticipation. "Well then, as teacher of Class A. I proclaim that from today onward; class is in session!"

* * *

 _'A creature that the Anbu of each village and even S-ranked nin couldn't kill... Yes. He will prove as a good test on how strong I've grown. It will prove that I am finally ready to kill him!'_

 _'Alright! With that much money, I could buy a lifetime's supply of ramen! Tako-sensei, get ready cause Uzumaki Naruto is coming for you, dattebayo!'_

* * *

 **Hope you enjoyed. Please review! ^^**


	2. Homeroom Time!

**I didn't really expect to get that amount of attention for the first chapter... I was expecting like... 3 or 5 at best. Well, best not to a look a gift horse in the mouth. XP**

 **I have a bit of spare time before my workload crushes me under mountains of paper, so I will dedicate that to making a few chapters here. Here's chapter 2 of Unkillable.**

 **Also, can any of you guess who this Koro-sensei is? Anyone who does gets an Internet-cookie!**

 **Hint: I've hidden a few small details already. Good luck!**

 _ **OrangeShinobi: Thanks. Though this was a spur of sudden inspiration kind of deal, it's nice to know that my first work is actually decent. :)**_

 _ **PainX65: Thanks for the support and your permission for me to write this fanfic.**_

 **Also thanks to a lot of you who favorited and followed this story within a few days of its birth. Arigato! Anyway, on with the chapter! Mush!**

 **Disclaimer: I don't own Ansatsu Kyoushitsu or Naruto. If I did, I'd be swimming in a pool of money right now**

* * *

It was a beautiful day in Konohagakure no Sato. The sun shone brightly over the village and its inhabitants. The birds flew over-head with fluid grace, their chirps like a sweet mellifluous song to the ears of the people. Flowers were blooming in the fields, littering the grass with many colors as the streams flowed with the soft and calm current.

Class A sat inside their classroom, observing from within the outside as they waited for their teacher to arrive and begin their daily classes. Their eyes all darted towards the door at once as they all heard it slide open, indicating either someone had entered or left. From what they saw, it was the former.

There was their sensei, ducking underneath the doorframe before coming into full height within the confines of the classroom. He smiled brightly at all of them, the eternal smile on his face bigger than usual.

"Ohayo mina-san!" he chanted, one yellow tentacle raised up in greeting.

They all stood up.

"Ohayo Sensei!" they greeted back.

It had been exactly one day since they had met him. One day since they were assigned their mission. One day closer to literal doomsday. One day closer to their shared goal...

The bipedal octopus tilted his large, round head slightly to the side. A green kunai sailed past his head before bouncing off the wall harmlessly and dropping onto the floor. His small eyes immediately locked on towards the perpetrator with an analyzing look. The class followed his gaze.

"Good morning to you too Sasuke-kun," he said cheerfully.

"Hn," was the monotone response the educator received from the stoic boy.

 _To kill their sensei._

The creature merely chuckled and extended his tentacles into his drawer on the teacher's table, retrieving a roll of tissue paper. He took some from the roll and picked up the offending weapon on the ground with it. His extended tentacles placed the kunai on the Uchiha's desk.

"Good try Sasuke-kun," their sensei lauded, his tentacles having retracted back to their regular length but not before they had placed the tissue roll back into his drawer. "Attacking your target when he's least expecting it was an excellent move. _However_ ,"

He moved onto the podium and behind his desk; his yellow smiling face developing three green lines going across it horizontally.

"Planning is next to _worthless_ without the skill to back it up," the octopus intoned, his smile more mocking than cheerful. "I would not have become your teacher if I wasn't prepared to handle a class full of shinobi."

He looked at all of them, the green lines still as visible as ever.

"Let this be my first lesson to you all," he said. "It is always important to plan ahead, underestimation and overestimation are a shinobi's greatest weapons. Underestimate: It's always good in our line of work to have your opponent see you as weak.

This will give you an upper hand and will often surprise your opponent at any tricks you might bring into the fight. And always overestimate your opponent. Always think that they are stronger than they seem; it's always best to be prepared for any encounter you will have with them. However, without knowledge of fundamental basics, or the skills necessary, any planning in advance will be all for naught. It would be like building a house on sand and the rain sweeps it away; _foolhardy_."

A hand was raised.

"Yes Hirashima-san?"

"Sensei, isn't that a _bit_ unfair?" the student asked. Many nodded at her question.

Their sensei rubbed his head. His smile lost its mocking nature, the green lines disappearing from his visage.

"You still have that line of thinking eh?" he asked. At their nods, he continued. "Take note and keep this in mind: we are shinobi, _not_ samurai. Two sides of the same coin. Samurai are honorable and have a code of conduct they strictly observe called the Bushido Code, and will never take the life of an unarmed opponent. A good example of this would be Mifune-san from Tetsu no Kuni.

On the other hand, shinobi fight from the shadows. In otherwords, we fight dirty. If we see any way we can win a fight, we take it; even if it means using cheap tricks such as blinding your opponent by kicking dirt into their eyes and taking their life as they are disabled."

Many students suddenly looked horrified at the prospect.

"But remember this class," he said, his smile enlarging. "While we have our differences, one thing keeps us linked: We _have_ a choice because we are human. The choice whether or not to take a life. Life is precious; priceless and irreplaceable. Now, I won't tell you what to do. As a teacher, my responsibility is not to tell you what is right, but to help you discover _how_ to make the right choice and _why_."

"Do you understand? I understand if you find this hard to take. The prospect of taking someone's life is never easy... " The class shakily nodded, but some more reluctantly than others.

"Hai sensei!"

"Very good!" their sensei said. "I would normally start class now with a roll call, but it seems we have one person missing among us."

The class blinked in confusion before looking towards the one vacant chair in the room.

The yellow octopus smiled. "And from what I can hear, he should be here right about..."

The door slammed open with a crash, startling many and causing multiple students to jolt backwards in surprise.

"Now,"

At the door stood a blond, wearing an eye-searing orange jumpsuit. His breathing labored, as he took deep-breaths to catch the air his lungs missed.

"I made it!" he quickly jumped up in joy, a grin as large as their sensei's making its way onto his face. "Uzumaki Naruto, the future Godaime Hokage is here!"

The bipedal octopus looked at the blonde with acknowledgement and a large smile. "Ohayo Uzumaki-kun. Please take your seat, we're about to start class."

The blond grinned at his teacher. "Hai sensei!" and made his way to his seat, but not before stopping mid-way, his eyes glued to his octopus of a sensei.

"Sensei, what are the flowers for?"

Many students looked confusingly or mockingly at the blond for the seemingly stupid statement, until they turned their eyes to their teacher and saw that, indeed; their sensei held a vase full of lilac-colored flowers in his arms/tentacles, along with a black notebook with a label that read "Roll Book".

"Yoku yattane Naruto-kun! **(1)** " their sensei's face shifted color from yellow to red, with a circle in a deeper shade of red appearing on his face. "You are the first to notice among your classmates!"

The now-red octopus placed the flower vase on his desk, and placed the Roll Book flatly on the table. "To answer your question, I merely thought that the classroom could use a little more brightening so I went to Yamanaka-san's Flower Shop and bought a vase of Hedera flowers as they looked so pretty. Don't they look nice?"

Most of class laughed in unison at the innocent, and rather child-like action. Yes, their new sensei was definitely not what they had expected.

The blond threw a thumbs-up. "They look _awesome_ sensei!"

"Nurufufu..." the educator laughed, his face turning back to yellow. "I'm glad you agree Naruto-kun. Now take your seat please, we are about to start class."

The Uzumaki rubbed the back of his head sheepishly. "Sorry sensei, I'll go now." and finally made his way to his seat.

"Alright, now that everyone's here," their sensei grabbed his Roll Book from the desk, and opened it. "Class will now begin!"

* * *

The bell finally rang out.

"That's the Lunch bell." their sensei said looking at them from where he stood on the podium, chalk held in one tentacle's fingers. "Are you all finished taking all this down?"

The shinobi-in-training dropped their pens, and closed their notebooks; having just finished taking down the notes on the blackboard after 4 and a half hours of discussions and lectures before responding.

"Hai sensei," they responded.

The octopus's face became a familiar red with a circle once more. "Good! We'll pick this up again, but for now you're all dismissed for lunch!" he chimed, much to the delight of his many students.

"Now," the teacher put the chalk back down, and walked over to a window and slid it open. "If you excuse me, I'll be taking my lunch as well. I'm headed to Mizu no Kuni; from what I've heard, they serve some very delicious seafood delicacies, and my wallet does not take well to being late!"

He waved good-bye before blasting off with a sonic boom out of the classroom window, and into the sky; a strong gust of wind rushing past the class as their sensei moved past the sound barrier.

Many students looked on in awe and utter shock, some even with avid curiosity. Some of them stood up and stretched, laughing while doing so. This seemed to snap many out of their shock-induced stupor and laughed along with them. If one looked carefully, you could see that even the normally stoic and apathetic Uchiha had a gentler slope to his uncaring facade.

"Man," one student called out, mirth obviously evident in his voice. "He might seem weird, but he's a pretty damn good teacher!"

Multiple voices voiced out their obviously shared sentiments about their octopoid teacher.

"Yeah," a female student said. "He might move fast, but the way he teaches is pretty fluid and easy to understand. He's also pretty funny,"

"You're not the one who got sent to the back and had to stand for an entire hour..." another student grumbled out, arms crossed.

"Well..." a male student expressed. "You did keep interrupting Science period by throwing shuriken at him when his back was turned..."

A snort was heard. That was the final straw, and many students burst out into a loud fit of laughter.

"Mendokusai..." one student droned out, covering his ears and planting his face down on his desk.

It had been during Science period when their teacher was busy with writing down his lecture and notes about basic biology, explaining the necessities of the subject to their line of work; even as menial as it was to study for most of them who would rather be on the field practicing throwing weapons or studying more interesting subjects. It was at this point that a student, Watanabe Hideki, had started throwing his weapons at their sensei, in an effort to kill him.

All it got him was a stern lecture about disrupting their studies, and being sent to the back of the room to stand for the rest of the period.

"He did apologize afterwards though," a sympathetic student placed a hand Hideki's shoulder in a placating manner. "He even gave you an incentive."

Their sensei, after Science period had finished, had immediately gone over to Hideki and apologized for having sent him to the back. The class had watched the entire exchange between teacher and student and soon saw how much their teacher did genuinely care for them, despite having met only one day prior.

 _"It's good to have goals." their sensei said approvingly, his face red with a circle once more. "My presence here and your bloodlust towards me is what binds us together. That is the only way I know how to describe our bond; shinobi and target, student and teacher. However, if your goal blinds you towards the reality of things, it is no longer a goal. It's a hindrance. I could not have you keep interrupting the class in your efforts to kill me, and sacrifice the quality of education you receive as of a result."_

 _He then approvingly patted Hideki's head to the amusement of the class. "I have to commend you though. Your timing to kill me, much like Sasuke-kun's, was most excellent! You just lack the proper experience and technique to perform it properly. Ace the upcoming test in Science, and I'll give you another shot!"_

 _"Nani?!"_

Hideki sighed.

"I guess... I'm still salty though..."

"Since when are you never?" a female student shot back causing Hideki respond to her with a very rude gesture, having another bout of laughter to erupt among the students.

"Okay, all joking aside, we should probably break for lunch. We'll figure out a way to kill sensei later."

"Yeah," a rather chubby student said. "I'm starving!"

The class laughed once again.

* * *

After lunch, the students of Class A were treated to a very strange scene as they entered the classroom.

There was their sensei, smiling widely as ever behind his desk... with two large sacks placed on the table in-front of him.

"Eh, sensei?" a student asked.

"Yes, Chiasa-san?"

"What's that?" she asked, staring curiously at the sacks; many of her fellow students imitating her curiosity.

"Merely a few souvenirs from Mizu no Kuni," their teacher said nonchalantly. "Nothing of importance,"

In the Hokage Tower, Sarutobi Hiruzen, the Kami no Shinobi and Professor, threw his pipe against the wall in submission and began crying in pitiful way that no Kage should ever be seen by his shinobi. There, on his desk, sat an unraveled scroll marked with the symbol of Kirigakure and five large bags placed on the floor next to his desk.

 _"Dear Sandaime Hokage,_

 _We would like to express our sincere gratitude with your rather surprising support of our attempts here in Kirigakure, after you rejected Mei-san's request for Konoha's support some time ago. Thanks to you and our combined efforts, we have managed to restore proper order to our village after unseating our Mizukage, Yagura. The shinobi you sent was very capable and crucial to our victory. Thanks to him, we lost only a minor part of our forces and he subdued Yagura quick enough that he was not able to fight at full strength._

 _We commend your ingeniously misleading plan. You truly do live up to your nickname as the Professor. It was best that Yagura were to think that we did not have your support only for you to send one of your best shinobi in the guise of a delivery mission here in Kiri, with their true mission being espionage and infiltration._

 _As an expression of gratitude, we have sent back your shinobi with a sum totaling 5.3 million Ryo for your troubles, and an extra 2.3 hundred thousand Ryo for the shinobi who you sent. He is deserving of the highest praise, and shall be remembered here in Kiri, along with Konoha itself as a whole. We have also included a treaty regarding trade agreements and such between our two villages as is fitting._

 _Thank you._

 _Signed,_

 _Sato Kichirou, Daimyo of Mizu no Kuni"_

 _'I'm getting to old for this shit...'_ the Sandaime in utter dismay. His Anbu guard that were stationed around his office had no idea what to do, and simply settled for sweatdrops.

* * *

"A-Ano.. s-sensei?" a meek voice asked.

"Hai Hinata-san?"

"Um... w-what's your n-name?" she asked, twidling her fingers together in a nervous manner; her face as red as a baboon's rear end. "Y-You never i-introduced yourself..."

She gave a quiet "meep!" and hid her blushing face behind her hands.

 _'She's a nervous wreck...'_ was the disillusioning thought of many in the class.

"I don't have one," was the oddly cheerful voice of their teacher, surprising many in the class about that one fact.

"Well..." another student voiced his concerns. "We can't exactly keep calling you just sensei... It's just downright rude..."

There were simultaneous nods among the students.

"Souka..." their teacher placed one tentacle under his head, right where his chin would supposedly be. "Very well then! Hinata-san, since you were the one who pointed it out, why don't you give me a name?"

"N-nani? W-why m-me?"

"Because," the teacher's smile grew larger. "It's only fair. You cared enough that you asked me for my name, even when many of your classmates paid no heed to it."

That cause many to look down in embarassment, looking sheepish.

"W-Well... okay..." the female Hyuga heiress stammered. "Y-You're our u-unkillable sensei... s-so w-why not K-Koro-sensei...?"

The octopus rubbed his head in deep contemplation. He suddenly looked up and smiled widely.

"I like it!" he proclaimed, his face a red hue with a circle once again inside it. "Okay class, from now on, I will be known as Koro-sensei!"

The class grinned towards their newly-named teacher. "Hai, Koro-sensei!"

Uzumaki Naruto laughed. "No way! To me, you're still Tako-sensei!"

Majority of the class couldn't hold it in. They burst out into guffaws.

Their sensei turned red, not in approval but embarassement. " _T-Tako-sensei?!_ "

* * *

 **Hope you guys liked it. Please leave a review. It feels nice to know that my work is appreciated. Comments and critiques will also be appreciated. ^^**

 **Thank you for reading. This is Sensei, over and out!**

 **1) Translates to Good Job Naruto-kun!**


	3. Study Time!

**This might be the last chapter that I post for a good long while so I'd rather post it now, rather than later.**

 **I hope you guys do enjoy this chapter, and the story as a whole. This one stars Naruto, finally reached that point!**

 **Disclaimer: I do not own Naruto or Ansatsu Kyoushitsu. :P**

* * *

The alarm clock was what always got Uzumaki Naruto awake in the morning... even if he did only wake up several hours later. He would then get up, heat some water, take a bath, get changed into his favorite jumpsuit _(Who cares what everyone says? Orange is awesome!)_ , eat some cup ramen, then head for the Academy for another boring day of _studying_ with Koro-sensei. After classes he would quickly get out of the Academy but not before bidding Koro-sensei goodbye, do some training until he nearly passed out, then head home to eat dinner and sleep. He would then repeat the process again the following day.

Today however, was different. It wasn't the loud ringing of the alarm clock that got him up, nor the loud rumbling of his stomach indicating it was breakfast time. No, it was none of this things.

This time, it was a scent. A wafting aroma filled his nostrils as he slept like a baby, tantalizing just by the smell alone, and it was a scent he could identify very well. It was the smell of food, warm and ready for consumption.

 _'Urgh... what time is it...?'_ the Uzumaki irritatingly thought.

He blearily opened one blue eye, gazing at the alarm clock on his bedside table. It read 5:30 am.

 _'Are you kidding me...?! It's so early! The Academy doesn't even start in another 2 hours!'_

He slowly turned his gaze towards the location from which the smell was emanating from and, to his eternal shock and surprise, saw that on his table, food had been set out upon its surface.

Quickly scrambling out of bed as fast as he could and being careful not to trip over anything, he rushed over to the table and saw the feast that had been laid out, its aroma very appealing to his sense of smell. Laid out on the table was a traditional Japanese breakfast, something that they had dwelt on a bit during Home Economics discussions. _(Hey, he paid attention to Koro-sensei at times!)_

It was rice; with pickled daikon and a raw egg on top of the rice. At the side was natto, ume boshi, miso soup and some fresh grilled fish with nori. In a bowl next to the plate was a small salad dressing, and a cup of warm milk all sat there on his table. And they all looked so delicious...

He salivated.

 _'But wait,'_ his thoughts interrupted him, indicating at him to be alert. He looked at the food suspiciously. _'I didn't make this; I don't even know how to cook! All this stuff is way too expensive for me to buy anyway! So that just means...'_

A sudden splash of water and a scream was heard from his bathroom.

 _'An intruder!'_

He quickly grabbed a kunai from his pouch that was set on his desk, gripping the weapon tightly in his hand. He silently crept to the ajar door of his bathroom, his footsteps light and quick. His eyes looked for any signs of a trap, but alas, there was none. He could still hear whoever was inside his bathroom uninvited in the early hours of the morning mumbling and fumbling about.

 _'This is horrifying... Never thought... must die...'_ he heard the intruder speak softly. His eyes widened at the monologue. His senses were more acute than most.

Solidifying his will and nerve, he breathed in deeply and reached out for the doorknob. He quickly pushed it open, and charged inside, only to feel something slippery beneath his foot. He yelped and tried to gain some semblance of footing but it was in vain, his kunai flying out of his hand and out of reach as his arms flailed about trying to help him regain his balance. He comically crashed onto the floor, face first.

He quickly regained his composure and saw that what he had slipped on was a wet bar soap that had been on the floor of the already wet bathroom floor. And a few feet away from it was his kunai. Right next to...

 _'Eh...?'_

His brain shutdown momentarily from the sheer absurdity of the scene he witnessed before his eyes. It wasn't something that he was prepared to cope with, dammit! Hell, they had not received training for any sort of situation like this, even with Koro-sensei's ridiculously, insanely large manuals. Speaking of which...

What caused his brain to shutdown you may ask? Well it was this:

There was Koro-sensei, his _teacher_ , face no longer yellow and smiling, but white and poker-faced; wearing a cleaning outfit, complete with a bandanna around his head. In sensei's tentacles were a couple of sponges and rugs, soaked to the brim with water and soap. And from the looks of it, was just cleaning the floor and had just finished with the _toilet_ , if the pearly white bowl was anything to indicate.

His sensei looked at him with a blank expression. He raised one tentacle up in greeting.

"Ohayo Naruto-kun," Koro-sensei greeted.

At that point, his brain seemed to have finally caught up with the situation on-hand. He yelped and jumped backward, pointing accusingly at his sensei/intruder.

"T-Tako-sensei?!"

* * *

Naruto's eyebrow twitched.

A couple of minutes had passed since he found Koro-sensei cleaning away in his bathroom _(He liked it just the way it was!)_ , and his teacher had given him a few minutes to calm down. During that time period where he fought violently against the overwhelming urge to die of a heart attack _(He wasn't gonna die! He hadn't even made Sakura-chan go out with him or even become Hokage yet!)_ , his sensei had somehow managed to get changed back into his teacher's uniform and had sat him down at the table and made coffee in-front of him. _Dammit Tako-sensei!_

And now, his sensei had been blowing away at his mug of coffee for the past five minutes. And it was ticking him off! How long was he gonna take?!

"Just drink it already would'ya?!"

His sensei's flatboard face shifted back to its regular yellow and smiling countenance, and gave a small smile at his student. A tick mark developed and throbbed on Naruto's temple.

"How are you Naruto-kun?" his sensei asked with sincerity, as he placed his coffee mug down on the table.

That did it. "Is that really all you have to say?! After you broke into my apartment!?"

"Nurufufu..." his teacher merely responded. "Do you not remember Naruto-kun?"

"Eh? What are you talking about Ero-Tako-sensei?! You're not making any sense!" This time, it was his teacher who seemed to have developed a tick mark.

" _Don't_ call me that!" his teacher retorted sharply, with fond annoyance.

Koro-sensei quickly reigned in his slight annoyance, with a hint of fondness at the new nickname his most active and troublesome student had given him yet, and sighed.

"Naruto-kun, you passed out on the training field last night." his teacher bleakly informed him, agitation and worry obviously evident in Koro-sensei's voice.

"...Huh?"

"You passed out Naruto-kun."

Naruto was confused. _He passed out_...? How...? Stamina had always been his best point!

"Nevertheless, I'm glad that you're okay now Naruto-kun." Koro-sensei smiled at him. A true, and sincere smile aimed at _him_. "You really had me worried there."

 _"Look.. it's the demon..."_

 _"Shhh! That's a secret remember! You could get executed for that!"_

 _"I'd better tell my kids to stay away from him..."_

 _"My parents said you're bad and that I should stay away from you."_

Koro-sensei then suddenly stood up and made his way towards the door of his apartment, making sure to place his chair back in proper order beforehand.

"Eh? Tako-sensei?" the Uzumaki voiced in confusement as his sensei opened the door.

"Eat your breakfast Naruto-kun, it's the most important meal of the day." Koro-sensei said through his never-ending smile, his tone soft and caring. "And get ready, the Academy starts in just a few hours."

And with that, Koro-sensei ducked underneath the doorframe and closed the door.

Naruto looked towards the calendar on his wall. It had been one week since he had first met the figure named Koro-sensei...

* * *

"He really doesn't know... does he?"

"I don't see what you mean."

"Don't try playing dumb; you forget that I'm a _teacher_. The kids try to play dumb nearly all the time with me."

"And that's something I can take away. I don't know how you figured it out, but I'll let it slide just this once. Frankly, I don't see how it's any of your business; you're just his teacher and walking-bounty." the elderly man looked blankly at him. "You only have to tolerate him for 3 years, depending if they manage to kill you while they're still at the Academy that is, and then he's gone. You don't have any real need to involve yourself with him besides school-work and them plotting your murder."

Koro-sensei fumed. "I'm not an idiot; _anyone_ with half a brain can put two-and-two together! Do you have _any_ idea what his living conditions are? I found _3-week old spoiled_ milk in his refrigerator! I had to buy groceries just make sure he had enough to eat besides all those instant ramen cups in his cupboards!"

"I am painfully aware, _thank you very much_." The Hokage spat out. "Also, no one asked you to do that; you chose to do that _yourself_ , so don't go pointing fingers at people. Don't think I don't care for him as well. I've known him longer than you have and have done many things to make his life as bearable as possible; he's like a grandson to me. So don't come to me feeling all righteous when you have just come into his life _now_."

" _Bearable_?" the teacher breathed out. "You call that _bearable_?! If you truly do care for him, tell him the _truth_!"

"Naruto-kun has been given a great burden, something his parents trusted him with with their own lives. Even I refuse to disrespect the will of the dead." The Sandaime spoke seriously, his KI barely restrained. "His parents were formidable and had many enemies. As naive as he is now, it's not _safe_ to let him know. He will know when the time is right. And as per the condition agreements, I'm ordering you not to speak of it any way, shape _or_ form. Just do what you have to do as their teacher and let them try to kill you while you're at it, as it says in your conditions, and _Nothing. More_."

"...Hai _Hokage-sama_..." It was reluctant, and grounded out by the skin of his teeth. He turned around, looking away from the aged elder but not before giving his parting words.

"A teacher doesn't just teach academics. He teaches and guides a student on the proper way to live. A teacher who teaches from a textbook and not from the heart, and only seeks the growth of his students' future in the academic aspect, and not as persons, then that teacher is not a teacher at all, but a master calling out to his slave."

He turned around and gave the Hokage a solemn look and left the room, with the door closed behind him.

Sarutobi sighed in frustration. ' _Damn you Minato..._ '

* * *

The orange-clad blond laughed gleefully from atop the Hokage Mountain using a pair binoculars as he saw the fruit being sold by one merchant turn multiple shades of brown as the pending customers/buyers looked at his produce with sudden shock, much to the vendor's panic.

 _'Try selling me overpriced stuff will ya?'_ He inwardly laughed maniacally.

It was something he would do. The vendors would try to increase prices on him, he would refuse, and then he would later strike back full-force with a prank full of vengeance. They weren't going to one-up the Prank Master from Hell!

As he cackled, the Uzumaki suddenly felt his stomach rumble in hunger. He stopped mid-laugh and rubbed his head sheepishly.

 _'I guess I'm getting a bit hungry hehe...'_

With that thought in-mind, he slowly got up and started his trek back to his crummy apartment, cup ramen filling his mind. He drooled slightly, he would deny it if anyone saw him though.

To his utter confusion, he would later find that on his table was bags full of groceries, packed with veggies *shudder* meats, and even treats of the like, complete with a store receipt and a note.

 _"Enjoy! Eat healthy and grow strong, and you'll be Hokage in no time!"_ was all it read.

* * *

"And that's it for today everyone," said Koro-sensei as the bell rang. "Make sure to do your homework, page 11 of your Basic Geometry books! We will discuss the answers tomorrow!"

"Hai sensei!" the class responded.

"And remember, you have training with Iruka-san tomorrow based on our new schedule!"

"Hai, sensei!" Though this one was more nonchalantly chorused out by the class.

A few minutes later, nearly everyone had left the room. Some had hung back and waited for their friends to finish packing up before leaving together. It was a sight that warmed his heart. He loved teaching...

"Uh... sensei?"

He was surprised when he turned his head and saw the mop of blond hair that belonged to one Uzumaki Naruto in-front of his desk, holding his Geometry text book in his arms.

"Yes Naruto-kun?"

The boy looked embarassed. "Can you... explain it again please? I tried but... I _still_ don't seem to get it." He bit out in frustration.

"I'll never become Hokage like this..."

Naruto then felt his sensei plop one tentacle over his head. "Don't worry Naruto-kun; I'll help you. It's my job as your teacher. We'll call it your cram session!" Koro-sensei smiled at him.

The blond fought back the tears that threatened to well up in his eyes. "Arigatou... Koro-sensei."

"It's no problem Naruto-kun." The teacher said warmly in reply.

"Now don't think I can't see the kunai Naruto-kun. Remember the rules, no weapons during lessons. Keep it as much as possible during breaks and personal time."

The blond blushed bashfully. "Hehe... sorry sensei."

* * *

"Now, the diameter of the circle is unknown. All we have is the measurement of two intersecting chords, a tangent line, Angle BDC and a secant. Now what you do you need to find the measurement of the second arc?" Koro-sensei asked him.

"You... multiply the measure of the vertical angle of the intercepted arc by two, but since they are vertical therefore congruent, we can use the measure of the vertical angle." Naruto answered, unsure. "Right?"

Koro-sensei's face became red. "That is correct Naruto-kun!" he praised his blond student. "Now how about-"

"Hey... sensei..."

That stopped his teacher mid-question. "Yes Naruto-kun?"

"It's been a two months since I asked you to tutor me..." the blond shakily spoke, his voice cracking. "I know that you tutor the others who are also having a hard time in other subjects..."

"And?"

"So why...?" the Uzumaki asked, voice raw with emotion. "Why do you still care about me? _Me_?! The class clown, the failure, the _deadlast_ , the scapegoat! Why do you bother with yourself me... no other teacher ever did! Why do you do this for me? I know that you're the one always filling my fridge with food to eat! Even the civilian kids are better than me!"

He his felt tears stream down his cheeks.

" _I promised myself I'd never cry cause a Hokage doesn't cry and it never solves anything! Why am I such a failure...?_ "

His eyes snapped open when he felt something soft wipe away his tears. He saw a tissue, being pressed against his face by one of his sensei's tentacles.

"You're _not_ a failure Naruto-kun," his teacher told him, placing the Geometry book down on his desk. "You're my student, and I'm your teacher; shinobi and target. That's how our bond works remember?"

"You can be selfish, impatient and a little insecure about yourself and your shortcomings." His sensei spoke with a solemn voice. The words cut deep _(sticks and stones may break my bones, but words cut deepest)_. "You make mistakes, you can get out of control, and at times are hard to handle..."

The blond felt tears come to his eyes as his sensei continued. However, before he could break down; any doubt the Uzumaki possibly held were immediately thrown away as his sensei spoke once more.

"But I am your teacher. So if I can't handle you at your worst, then I don't deserve you at your best." Koro-sensei had turned red with approval once more. "So keep your chin up, and keep smiling. Believe in yourself, and you're already halfway there."

As his sensei and target continued to smile, that was all he needed before he broke down into tear-wracking sobs once more.

"I'll always be here Naruto-kun,"

* * *

The Uzumaki was up before his alarm clock had even rung. He'd already done his homework before crying himself to sleep last night, brushed his teeth, took a bath and made himself a healthy breakfast with toast and some warm milk provided by Koro-sensei a few days earlier.

He looked at himself in the mirror and smiled. Gone was the orange jumpsuit; replaced with a white jacket that had orange stripes around the sleeves, underneath which was a black shirt. Black pants covered his lower half, with his weapon holsters secured firmly to his calves; shinobi sandals in place.

He made to grab for his green goggles and strap them to his head, before stopping himself and looked at the item before him.

 _"You like to make yourself look like the fool to gain the attention you lack," his sensei spoke. "Don't deny it; I've seen it before. However, not in our classroom. My job as a teacher does not just include me helping you just succeed in life, but to help you find yourself while you are on your path to greater heights. You have the potential to be great Naruto-kun; that much I know. Possibly even stronger than me."_

 _The Uzumaki's eyes widened. "You're kidding sensei... right?"_

 _"I don't think I am Naruto-kun." Koro-sensei replied. "You have unrivaled potential. All you needed was a proper guide to show you the way."_

 _"You mean... you?"_

 _His sensei laughed. "Nurufufu... don't think it will be that easy Naruto. Success is only gained through hard-work and perseverance. I'd be making things too easy for you."_

 _Naruto balked. "Eh? Then what was the point of telling me?"_

 _Koro-sensei laughed once more. "That's the beauty of it. It doesn't need to have a point; words can mean many things for many different people, many different scenarios and conversations. However, here's some incentive. Place within the top 10 of the class come graduation, and I'll stand still for one entire second and let you try to hit me for that one second."_

 _"I didn't really understand the first half of whatever you just said, but that last part sounds good to me! You got yourself a deal Sensei!" The orange-clad boy grinned and stuck his hand out._

 _"Nurufufu..." the teacher grinned and shook Naruto's outstretched appendage with his own. "You'll understand in time Naruto; you just need to grow a bit more. But until then, I'll look forward to it."_

 _"Are you making fun of my height?" the blond's eyebrow suddenly twitched._

 _"Like I said before; it's all up to you about what I mean." The teacher laughed and dodged a half-hearted swipe of a kunai at his head._

 _"I'll say it again; you can become stronger than me with time and room to grow." Koro-sensei's face suddenly had three green lines across them. "But until then, I'm still your teacher Naruto-kun! So killing me won't be that easy!"_

 _'I don't need it anymore,'_ The Uzumaki thought with determination. _'I don't need to hide myself and look for attention anymore. I can be me...'_

He placed an enclosed fist above his chest, right where his heart would be. _'Arigatou Tako-sensei...'_

He grinned at his reflection. "Get ready sensei! Cause this time, the new and improved Uzumaki Naruto is coming for you with everything he's got! I'm taking that prize dead-or-alive! Dattebayo!"

"Hey, shut up will ya! Some folks are trying to sleep here!"

"G-Gomenasai...!"

* * *

Koro-sensei would later find that out to be entirely true. Naruto had proceeded to booby-trap the hallway which he regularly came from, had cut up one of his kunais in shards and placed the remains in a bucket over the door. The entire day was spent with bouts of laughter, scolding and fun merry-making. But most of all, learning.

The teacher would later find a mug of warm coffee placed over his desk by dismissal time with a note attached to it.

 _You never did finish that mug of coffee you had when you first came to my apartment._

 _Arigato, Koro-sensei!_

 _\- Uzumaki Naruto_

* * *

 **Tell me what you think. Leave a comment, review or a critique. They will be appreciated. ^^**


	4. Teaching Time!

**And I'm back! But not for long, probably a few days at best XP.**

 **Life has been really hectic recently! I've barely been able to write or think of anything besides work and school. Oh well, such is life; get a job to pay taxes and buy stuff the governement wants us to. Gumball was really spot-on...**

 **Okay, my rambling aside. I've finally managed to create Chapter 4 from the depths of my imagination-ridden brain! Yay! ^^**

 **I hope you all like this chapter! I've put quite a bit of effort into this and I will not let it be for naught! Thank you and enjoy!** **Also, big shout out to everyone who favorited and followed both this story and me! Thank you very much! I love you all! XP**

 **But one thing eludes me... how has no one guessed who he (Koro-sensei) is? I kinda hoped someone would guess it by now. Alas, it was not meant to be. Some were really close though, but not yet! Keep looking for those hints I've scattered all over! But you'll all figure it out once I've hit the Chunin Exam Arc; at least I hope so...**

 **Well anyway, on with the chapter!**

 **Disclaimer: I don't own Ansatsu Kyoushitsu or Naruto. I'm not an awesome Japanese mangaka. I wish I was though!**

* * *

Umino Iruka stared from where he stood at the corner of the classroom.

And stared again.

Maybe he could stare a little bit longer without standing out too much perhaps...?

Then again, he could as everyone else in class was doing as he was; complete with mouths hung agape. Their minds simply refused to render the impossible thought that dared to cross their minds. Even Uchiha Sasuke seemed to have taken time-off from his daily work of brooding to stare dumbfound. It just wasn't possible! Just as it wasn't possible for anything that wasn't human to teach in a classroom and expect the students to learn anything!

 _Oh wait..._

Looking around the classroom, the Tokubetsu Jonin suddenly realized how moronic the statement sounded; and completely and utterly ironic.

 _'I need coffee...'_

What had gotten the class into such a tizzy, you ask?

There, sitting on his desk, was Uzumaki Naruto. Oh no, that part wasn't surprising; not at all. However what had caught their eyes and burned their retinas was _that_. Uzumaki Naruto, the Prankster from Hell, self-proclaimed Godaime Hokage, and deadlast of the class was, unbelievably, _Not. In. Orange!_

A few feet from where the scar-nosed Tokubetsu Jonin stood frozen, Watanabe Hideki had taken the opportunity and initiative to snap himself out of his trance. As if he were a robot, he looked to his side and immediately decked the student that stood right next to him.

The similarly shell-shocked blue-haired student and sudden target-of-incoming-and-painful-fist, suddenly went a good number of paces from brain-lag to brain-dead in the span of a few seconds and crashed face first into the floor; about as fast as their teacher going at Mach 2. Hideki then slowly retracted his fist and stared in awe of it, as if he had found the answer to every question in the universe.

"Huh." he said flatly.

The decked-student suddenly got up and glared at him, a huge tick mark throbbing on his temple. At the back of his mind, the brown-haired boy vaguely registered the bluenette by the name of Chiba Arata.

"Oi!" he yelled. For emphasis he pointed towards the rather large lump that had formed on his scalp, vaguely reminiscent of a potato. "What was that for?!"

Hideki shrugged. "I needed to wake myself up."

Looking around the brunette realized that his action seemed to spur everyone to take their eyes of the no longer _"Come kill me now!"_ clad blond, who had also taken notice of them and stared in their direction. Naruto's face was one shaped into utter confusion and face-value context.

 _'At least one thing remained consistent...'_

If it was even possible, Chiba's tick mark grew to drastic proportions. "That's not how it works!"

The brown-haired boy smiled back. "Could've fooled me,"

Chiba blinked.

"Kono yarou...!" If looks could kill, Hideki would've died a hundred times over, been revived; and then tortured sadistically with a tube full of wasabi.

Before the bluenette could jump the brunette and strangle the ever-living life out of him, something long and yellow had decided to plop down on their heads, and in Arata's case, right on his swelling lump.

"Itai...!"

The perpetrator seemed to have taken that moment to squeeze his face right between the two of theirs, forming a squishy yellow wall between them. Koro-sensei gazed for a bit at the no longer eye-scarring blond before smiling widely.

"Ohayo mina-san...!" he greeted brightly.

It would have been a nice sight to see, if their sensei wasn't restraining two arms held above him with his tentacles. In Hideki's and Chiba's hands, a bright green kunai was at the ready and prepped to make octopus sushi.

Naruto grinned back at their teacher.

"Ohayo sensei!" he responded cheerfully. The teacher in-question casually ducked underneath a thrown shuriken.

"Nurufufu..." laughed Koro-sensei. The bi-pedal octopus switched his gaze toward his two students beside him.

 _'I-is he... are his eyes focused on both of them...?!'_ The class sweatdropped.

"Now, now Chiba-kun..." the teacher placated, green lines coming to life upon his face. "While you are encouraged, required even, to kill in this class; it's preferable when it is aimed at me rather than your fellow students."

A gush of wind swept pass the students and they all soon found themselves seated in their proper seats. Koro-sensei blurred up-front behind his desk, his usual Roll Book and a new vase of flowers on his desk.

 _'Oh yeah...'_ the resident pinkette of the class realized. _'The last batch of flowers wilted away last week...'_

At the back of her mind, she registered that the flowers were no longer the lilac-colored Hedera flowers, but teal-colored roses that had taken their place.

"New batch of flowers sensei?" Yamanaka Ino asked her teacher, grinning. She liked flowers, her family did own the business afterall!

"Yes they are Yamanaka-san,' their sensei gently smiled back. "Pass Hotaru-san **(1)** my thanks. The teal-roses do go well with the classroom's background."

Ino gave a small salute. "Hai sensei!"

"But for now... there's a much bigger issue that needs addressing." Koro-sensei spoke determinedly.

The class was suddenly taken aback at their sensei's tone of voice; it was much more solemn than they had ever heard it before. Even Iruka was surprised. Usually, the octopus was the jovial one in the class, matched only by Uzumaki Naruto.

They leaned forward, anticipating what their sensei would say next; their chairs tilting slightly forward. It was silent, breathing barely heard as the class waited with bated breaths.

And then, in the silence of it all... Koro-sensei spoke.

"What do you all think of Uzumaki-kun's new outfit?" he inquired jovially.

Majority of the class face-vaulted onto the floor while still seated in their chairs. Iruka, being the more responsible adult in the room, simply sweatdropped. At that point, many students seemed to have recovered and suddenly leaped up, pointing accusingly at their teacher who was feigning innocence but looking guilty as sin.

"Really sensei?!" they asked in utter disbelief.

"I was merely curious. I was taken by surprise as well," he said sheepishly. The bipedal octopus rubbed his yellow head with one tentacle in an embarrassed manner.

The Uzumaki stood up angrily.

"Hey, what's wrong with it?!" the blond fumed. "Never seen a guy change his clothes before?!"

"You not wearing orange means the apocalypse is coming," said the class flatly, surprisingly including Iruka, Sasuke and even Nara Shikamaru.

"I'm not that bad am I?! And orange is awesome dattebayo!"

As Class A bantered between themselves, from where he stood, Iruka smiled.

When he was assigned here, this wasn't at all what he had expected from a literal assassination classroom.

* * *

 _"Eh?" Iruka stared blanky at the small beady eyes that stared at him from the desk, ignoring the giant smile on creature dubbed Koro-sensei's face._

 _"Nani?"_

 _He raised the form in his hand to emphasis his point._

 _"I'm being assigned as this class's Physical Instructor." he replied flatly. "Signed by Hokage-sama himself."_

 _It had been a few weeks since Iruka had first met Koro-sensei and Class A, and the Hokage had recently decided to name him as the Physical Instructor of the class as he already knew of the existence of the creature known to his students as Koro-sensei. The scar-nosed now Tokubetsu Jonin swept away the thoughts of the Sandaime Hokage. Who the hell randomly assigned a shinobi to a mission (an S-rank mission at that!) without information and continued to read porn without a glance?!_

'Nani!? An S-ranked mission? That same one?!'

'Yes, and you are granted the rank of Tokubetsu Jonin until further notice. Now move along, I need a break from all this paperwork; I don't want to end up like Onoki.'

'But-!'

The door was then slammed in his face.

 _Iruka sweatdropped._ And that was suppose to be their leader...?

 _In the blink of an eye, the bipedal creature was in-front of him and had grabbed him by the shoulders, looking at him with tear-tracked eyes; looking at him as if he had just committed the greatest of heresies._

 _"B-But, a-aren't I their t-teacher?" the weeping sensei turned and looked at his sweatdropping students. "M-My students e-enjoy my training lessons!"_

 _He spoke no words, but his eyes told all they needed to know: "Right?"_

 _It was here the silent Aburame Shino spoke._

 _"Sensei," Shino spoke with a surprisingly deep voice for someone his age. "While you're training lessons are very informative, especially in terms of analysis of your abilities and our current ones; they just are not logical for us at this stage to perform. While you did perform a very useful demonstration, I'm afraid doing jumping jacks at that rate where we form afterimages at our age and level will simply not be possible."_

 _The class blinked in unison._

 _A student stood up and pointed shakingly at Shino, gaining a raised eyebrow from the Aburame._

 _"I-It t-talks!?" he screamed in panic._

 _The dam finally broke away and the river rushed forward; the class shrieked._

 _"N-Ninjutsu!" A student shouted._

 _"Ie! It's a Kinjutsu!" Another pupil refuted, a female this time._

 _"We must inform Hokage-sama immediately!" Another shouted in urgency._

 _"What are our orders in this type of situation?!"_

 _"How come his voice is deeper than mine?!" One male student shouted loudly in outrage._

 _Everyone suddenly stopped mid-rant and looked at the student in question with "What-the-hell?" expressions dawning on their dumbfound faces. Said student blushed in embarrassment before looking at them with an indignant expression._

 _"What?!" he asked hotly. "I've been waiting for my voice to drop for a while! Now I find out he has a deeper voice than mine!"_

 _The class's panic seemed all but forgotten as one after another, joyous sounds of uncontrollable laughter erupted from the shinobi-in-training. Koro-sensei even approached the student and patted his back in sympathy, chuckling all through out._

 _As the sound of true laughter reached his ears, from where he stood; Iruka was no longer sure on what to properly think._

 _'What did I just get signed up for again...?'_

* * *

Iruka sighed with a smile present on his face. Yes that was one encounter he'd never forget any time soon.

"Now then," Koro-sensei spoke up amongst the banter of the class. "I'll start today's Roll Call. Please be seated and respond loudly when I call your name."

"Aburame Shino-kun?"

"Hai..." the voice that responded seemed quieter for some reason.

"Akimichi Choji-kun?"

The chubby boy took a break from snacking on his bag of chips and gave a muffled "Here sensei!"

"Aoyama Chinatsu-san?"

The black-haired girl looked at her teacher and gave a smile. "Present Koro-sensei,"

"Chiba Arata-kun?"

"Here..." another check.

"Fujimori Kenta-kun?"

The teacher ducked under a thrown kunai. "Present sensei!"

"Haruno Sakura-san?"

The pinkette raised her hand. "Present!"

"Hirata Kyo-kun?"

"I'm here!" the Hirata's voice called out.

"Hiroshima Fumiko-san?"

The girl brandished her kunai with a smile. "Here sensei,"

"Hyuga Hinata-san?"

"H-Here s-sensei..." a meek voice called out.

"Oh," Koro-sensei looked puzzled. "I can't hear Hinata-san; is she present?"

"I-I'm here sensei..." Hinata called out once again.

The yellow octopus scratched his head with his pen and sighed sadly. "I guess I have to mark her absent..."

"I'm here sensei!" To their surprise, Hinata had stood up and had spoken much louder and without a stutter present. Realizing what she had just done, she looked around, blushed and sat down; face as red as a tomato.

"Very good!" their teacher jovially exclaimed. "Now, moving on..."

"Inuzuka Kiba-kun?"

The Inuzuka grinned and responded "Present sensei!" before Akamaru had whined.

 _Bark!_

"Ah yes," Koro-sensei corrected himself immediately. "Akamaru-kun?"

Akamaru's tail wagged and he barked from where he was on Kiba's head.

"Kanagawa Jirou-kun?"

The megane pushed his glasses back onto the bridge of his nose. "Present and accounted for,"

"Kimura Chiasa-san?"

The female student grinned at their teacher. "Here sensei!"

"Miyagi Hachiro-kun?"

A cough was heard. "Present sensei..."

"Miyazaki Kenji-kun?"

A student raised his hand. "Present sensei!"

"Nara Shikamaru-kun?"

A vague mutter of "Mendokusai..." was heard before a pineapple headed student raised his hand lazily in the air. "Here..."

"Okuda Manami-san?"

"Here!"

"Ozaki Satoru-kun?"

"Present sensei," a student responded.

"Sasaki Asami-san?"

"Here sensei..." she responded in an averse voice.

"Shimada Kiyomi-san?"

A girl smiled from the back and raised her hand. "Over here sensei!"

"Toyoda Nobuyuki-kun?"

"Here!"

"Uchiha Sasuke-kun?"

"Hn." the raven-haired teen grunted. "Here..."

The Uchiha went back to looking out the window in his usual brooding manner, and personal brooding corner.

"Uehara Mamoru-kun?"

"I'm here sensei," a voice beside Shimada called out.

"Uzumaki Naruto-kun?"

The blond grinned from his seat, no longer clad in eye-searing orange. "Here Tako-sensei!"

Koro-sensei smiled wider. "Wakabayashi Katsumi-san?"

"Present!"

Another check on his Roll Book. "Watanabe Hideki-kun?"

"Here sensei..." Hideki drawled, earning a few chuckles from his classmates.

"Yamanaka Ino-san?"

The platinum blonde smiled from her seat beside Kiyomi. "Here!"

"And last but not least, Yamashita Masahiro-kun?"

"Here sensei!"

Koro-sensei looked up from his Roll Book and set down his pen on his desk before closing his book. He smiled at his students.

"Well..." he said in his regularly cheerful voice. "Since that's everyone; class will now begin!"

As the Roll Call finished and another day of learning began, the scar-nosed teacher looked at the class with a growing smile.

Maybe being a teacher wasn't so bad.

* * *

He took it back. Being a teacher was a pain is the ass. Especially the colleagues.

"Hey..." he glared towards the towering form of the homeroom teacher of Class A. "Why am I paying for this...?"

Iruka looked at the sweets piled on the counter and at the horribly disguised Koro-sensei who was standing by the cashier register with a worrying glint present in his small beady eyes that put the Tokubetsu Jonin slightly on his guard.

 _'He wouldn't be able to fool even a kid with that disguise...'_

Case in point, the cashier was looking oddly between him and the disguised teacher. He merely gave a shrug, telling her he wasn't so sure either.

"Well..." Koro-sensei said in a sheepish manner. "I spent most of my paycheck earlier this month. And I thought that since we're colleagues, you wouldn't mind doing this small favor for me?"

If looks could kill, Koro-sensei would be a pile of ash on the floor of the neatly cleaned supermarket.

 _'He calls this an emergency?!'_ Iruka's hand itched for the kunai in his pouch. He looked towards the civilian cashier and realized he could have more chances at killing the octopus later, not blow the mission and still keep it a secret.

He sighed and pulled out his wallet, much to the delight of his fellow teacher.

Looking at the smile on his colleague's face, the Tokubetsu Jonin could already feel his wallet become lighter.

 _'I'm gonna kill the Sandaime...'_

* * *

 **AN: Phew! And done!**

 **Well I hope you all enjoyed! Please leave a review, comment or critique! They will be welcome and appreciated!**

 **1) Ino's mom does not have an official name so I made one.**


	5. Assassination Time!

**I've been working on this chapter for a while now, and by working I mean formulating it in my head. I hope you all like it!**

 **PainX65: Thanks! You were very close with one of your guesses too! You got some stuff in your theory right too, just a few mistakes that will be shown in later chapters. Good luck and keep trying though! :D**

 **So on with the chapter!**

 **Disclaimer: I do not own Naruto or Ansatsu Kyoushitsu! I wish I did though!**

* * *

Something had been bothering Uchiha Sasuke since the start of their so-called 'mission'.

It was really ticking him off too; his brow twitching ever so slightly as he gazed out the window of the classroom in the comfort of a chair in the back. He ignored his classmates arriving one-by-one and trading with one another their greetings, accompanied with their large smiles.

His scowl deepened.

He didn't need people like them; they were merely a hindrance on his path to power in order to avenge his once might and great clan; on his path to kill him. And no, he didn't mean their 'unkillable' teacher that the Hyuga heiress had dubbed Koro-sensei.

A childish play on words, he thought. It was idiotic and bland; a mere mediocre wordplay with Korosenai which literally meant 'unkillable'. He scoffed, he refused to acknowledge that that thing was unkillable. His father would most likely be able to kill it with ease if he were still among the living; _that man_ more than likely being able to do better if he were given the chance.

Which he probably was, Sasuke mused. Missing-nin needed money to survive without the support of their village and regular pay, so bounties and mission requests of the darker kind would be their first choice for a source of income. He glanced at the vacant desk on the podium.

And with a bounty that large; it was impossible that anyone looking to cash-in on any huge wads of cash didn't know of the supposed 'secret' that was their teacher Koro-sensei. Hidden Villages were just pathetic like that.

Which led him back to his main point. His gaze shifted from the outside world and locked onto the few people that had already arrived in the classroom, looking at them with scathing and condescending scrutiny. He knew the problem that they shared; one even he possessed if he were to be honest with himself. A trait which he had realized with great frustration.

 _No one was making any real effort to kill Koro-sensei._

Sure there were attempts here and there with them throwing their kunai and shuriken at their octopus-like teacher, even attempting to stab him at certain points; and if he were to be completely blunt, they were utterly pathetic. It was something that a mere child playing Ninja would come up with in their type of situation! It was sickening.

 _'That's why I don't need people like them...'_ he thought disdainfully.

 _'Weaklings...'_

One would assume with such a large prize at stake and up for grabs, people would be more inventive and motivated to kill their teacher. _Keep all assassination attempts to personal time?! Who gave a damn?! If they were given the chance to try and kill him at any point in time, there was not one reason telling you otherwise!_

Sasuke silently fumed.

 _Idiots..._

The Uchiha gazed at the green kunai he had absent-mindlessly been fiddling with with his fingers, constantly flicking the dull, rubber-like tip of the weapon. He scowled even more as gazed at the weapon. Konoha hadn't even _made_ these weapons; donated by _charity_ of all things from Oto no Kuni.

If there was one thing that Uchiha Sasuke hated, it was pity and charity.

 _'To be drawn in by the very thing we're tasked to kill... I hate it...'_

There was a test today, a History quiz; one he had made sure to study for. At least Koro-sensei had one good use. As he gazed at the weapon in his hands, he came to his conclusion and resolve; even when the now common loud slamming open of the door indicated that the class dobe had arrived.

 _'If no one's even going to try...'_ he sent a scathing glare at the teacher's desk, tightly gripping the kunai in hands as it dug into his skin.

 _'I'll kill him myself!'_

* * *

"Okay everyone, time is up!" Koro-sensei exclaimed, his smile still as wide as ever. "Please pass your papers to the front!"

Multiple students groaned in unison and dropped their pens which clattered noisly on their wooden tables, a couple furiously scrawling down their answers on their test papers with as much time as they were permitted. A small few who finished earlier than most small grins on their faces as they watched their classmates panic in their rush to finish their test.

The bell rang all too soon, much to many students' chagrin.

Sasuke watched as their teacher went about collecting their papers, watching the pile in which his paper was located in. He wasn't worried about his test, not one bit. He knew he had gotten full marks; nothing less was expected of an Uchiha such as himself. It was painstakingly slow, to his utter annoyance; Koro-sensei taking small glimpses at the test results and giving off his comments to his students with a red face and an approving smile.

As their teacher finally reached his pile, Sasuke's heart raced as he saw the teacher walk over and reach for the pile of papers on the desk. It was time to see if those weapons truly did work after all.

As soon as Koro-sensei's tentacle had laid one touch on the pile, a loud and sudden bang similar to that of a gunshot resonated through the classroom, startling many students. Their teacher's face suddenly gained a panicked expression and quickly retracted his tentacles, leaping backwards while doing so; the pile of papers coming undone and floating onto the ground.

The sudden sounds of shocked and awed gasps was all the Uchiha needed to know that he had succeeded. There on the ground was one of Koro-sensei's tentacles violently blown off from the rest of his appendage, flailing wildly and spraying yellow mucus all over the wooden floor of the classroom.

Out of the corner of his eye, Sasuke noticed a test paper covered in small, unnoticeable green shards; a smug smirk forming on his normally stoic face.

 _'Hn. I expected as much...'_ the Uchiha thought with rising anticipation, his hand reaching for his weapons pouch. _'Do me a favor as your student and die, ne Koro-sensei?"_

He drew out his kunai and a pair of shurikens and charged at his sensei, much to the shock of his classmates who gasped and gaped at him. Koro-sensei seemed to be mimicking their expressions as he clutched his flailing tentacle which too was spewing yellow mucus vigorously in the air.

Sasuke threw his shuriken at their frozen teacher with pin-point accuracy; his sensei's eyes widening to the size of dinner plates, barely managing to avoid being struck with the anti-sensei shuriken flying his way. He ferverently leaned to the side in the quickest manner he could; the flying weapons impacting the board behind him.

Taking of advantage of his target's shock and surprise, he lashed out quickly and violently with his right arm, kunai held tightly in his grip and aiming to slice through his sensei with one swift stroke; knowing now that the weapon truly could rip through Koro-sensei like a hot knife through butter.

His sensei hurriedly avoided the oncoming weapon with apparent difficulty, but even still; Sasuke could feel that the kunai had slightly grazed the surface of his sensei's membrane-like skin.

He quickly slipped out another kunai hidden in his sleeve, thrusting his left arm forward to the surprise of their sensei on the second oncoming weapon mere inches for his still smiling face.

 _'I got you now...!'_

Before his kunai could make contact with its target, Sasuke's eyes widened to drastic proportions as he looked at the stump that was once one of Koro-sensei's tentacles. The stump ruptured and quickly elongated back to its former length and size, wrapping around his arm which held the incoming kunai.

He felt his bones shake as his arm was suddenly stopped mid-thrust, the yellow appendage coiling around his arm like a snake; tightening causing him to wince slightly.

 _'It's not over yet!'_ he resolved and he drew his right arm back, flipping the kunai in his hand that the blade was now aimed back at his sensei unguarded hind.

And then without reason, Koro-sensei smirked.

Two other pairs of tentacles suddenly appeared from the oversized-sleeves of their teacher's robes, quickly snaking their way around his other arm; pinning both his appendages down much to the Uchiha's utter shock.

 _'H-How...?!'_

"Nurufufu..." Sasuke gazed down onto the laughing figure of his sensei, confused and shocked; also taking notice of the heavier breathing pattern of the yellow bi-pedal octopus.

"Very impressive Sasuke-kun; most impressive _indeed_." Koro-sensei lauded. "Sticking bits of anti-me material on your test paper was a brilliant stragtegy, one that I had admittedly prepared for, but not anticipated so soon. What I didn't count on, however, was you taking advantage of the situation and trying to confront me in a forward assault. A most brilliant plan indeed!"

Koro-sensei turned his head slightly to look at his student's still-frozen arms. "And the applied technique in your assassination attempt must be praised as well. If I had not had any experience dealing with many shinobi all at one time, this pincer attack could have been fatal if not for my fast regeneration."

His teacher then slipped underneath his kunai, breathing a small sigh of what Sasuke assumed to be relief; his one free tentacle grabbing a role of tissue paper from his desk and wrapping the anti-sensei weapons in them before picking them out of his grasp before setting them safely on the table.

"Very well done Sasuke-kun; much better than your previous attempt!" Koro-sensei praised, releasing the vice-like grip the tentacles had on Sasuke's arms, the young Uchiha's shoulders slackening from the drawback. "You have obviously learned from that experience and have grown, even if only slightly! I give you full marks!"

Sasuke gave a scathing glare.

"Tch... whatever..." he muttered, before making his way back to his seat at the back of the classroom once more; making sure to swipe his weapons from Koro-sensei's desk much to the amusement of the educator.

Before he made it half-way to his chair he shot Koro-sensei with a dark look, malicious intent present in his eyes.

"You're not so unkillable afterall... are you Sensei?"

As he sat back down on his desk, he could make out that every single pair of eyes was locked on him. Great, just what he needed. Annoying...

The teacher merely shook his head before he addressed the class.

"Everyone please take your seats," he said, the class's attention switching from the now stoic Uchiha to him before slowly taking their seats. "Take this as an opportunity to learn. An experienced shinobi is an efficient shinobi; learning from one's past mistakes is what life is all about. Sasuke-kun failed the last time he tried and made sure to take what he had learned from that and applied it to improve upon what he had to work with. Knowing that I do not respond well to sudden changes in the environment, he did his best to capitalize on my moment of weakness and strike me from there!"

Their teacher's face became red once more. "This was truly a top-notch assassination! I now expect more from this class than ever before; so do your best and take in everything you learn, not just within the confines of our classroom, but in your everyday lives as well! That is what being a shinobi is about!"

"Hai sensei!"

The Uchiha's ears twitched.

"Baka-sensei... I never knew about any so-called 'weakness'." he said, a small glint appearing in his eyes as he slowly spoke in a mocking drawl. "So you don't respond well to sudden shifts to your surroundings eh?"

Koro-sensei blinked.

"...Eh?"

The class blinked in unison, before a malicious grin formed, coming to life on their now-sinister faces. At that moment, Koro-sensei immediatley knew he screwed up big time.

"N-No! W-What I meant was that Sasuke-kun was great in analyzing; so in effect-" Koro-sensei rambled on only to be cut-off by his class.

"Oh shut it sensei!"

The teacher started sweating bullets. "B-But I-!"

While Uchiha Sasuke didn't manage to kill their teacher that day in their assassination classroom, they had gained a valuable piece of information in return. A weakness; one their sensei had and could exploit.

 _Koro-sensei's Weakness #1: He doesn't take well to sudden changes in his surroundings._

* * *

"You know he has a sweet-tooth right? That could be something you guys could use."

The class blinked at their Physical Instructor, digesting the information he had just given them. Classes at the Academy had already come to a close for the day and for the weekend, and Koro-sensei being Koro-sensei had flown off to the Fire Capital right after dismissal after hearing of a festival to take place there tonight.

"Eh? He does?" the class balked.

Iruka nodded in a wise manner at the class of pseudo-Genin. "He does. Thought you would like to know; I heard you discovered a weakness today in class thanks to Sasuke."

"Why are you telling us this? Don't you want the bounty sensei?" Aoyama Chinatsu asked in a confused manner, majority of the class nodding their heads in agreement.

Iruka nodded, a small tick mark throbbing on his temple; pulling out his wallet from his back pocket and showing its contents the class could see why.

"He made me spend my paycheck on his sweets at the supermarket," the Tokubetsu Jonin spoke in a strained voice, his eyebrow twitching madly. "I'll ask this of you: avenge my wallet. I will not stand for this injustice!"

The class grinned and laughed at their second teacher much to his irritation and protest for them to take him seriously. It truly was a remarkable day for Class A, and with many more sure to come.

 _Koro-sensei's Weakness #2: He has a sweet tooth._

* * *

 **Well I hoped you guys enjoyed it! I plan on posting the next chapter in a few days after exams!**

 **Please leave a review, comment or critique! They will be appreaciated! Until then, see you next time! ^^**

 **\- Sensei**


	6. Lesson Time!

**Okay, first off: Merry Christmas everyone! May you all have a very joyous Christmas and New Year!**

 **All the favorites, follows and reviews I received are probably the best Christmas present I could receive as a writer. So thank you everyone! That being said, this will be the last chapter I'll post on any of my stories for the remainder of the year cause I intend to spend time with my family this Holiday break.**

 **Also, I'm in need of a Beta Reader. So PM me if you are willing to proof-read this story. Again, thank you!**

 **Now with that out of the way, here's Chapter 6! Enjoy!**

* * *

"Would you kindly tell me where I can find this man?" she purred, pointing to a small photo held in her gloved hand.

This statement could have been taken as is with nothing more needed to be explained. It certainly would have, had not the speaker been holding her addressee at knife-point; the kunai held softly firm to the exposed neck of her unwilling victim backed against the tree bark. He chocked slightly under her kind yet ruthless gaze, sputtering in a messy manner as he began pleading for his life much to her annoyance and amusement of her comrades who she could hear chuckling from the safety of the branches, cloaked in the shadows of the night.

She'd deal with them later; maybe a few hundred laps as _training_ would suffice. She shook her head; no she would not become like that. It seemed that Anko had affected her way too much with their many interactions in their small group. Kurenai would not approve, Hana would laugh her ass off and Anko would have screamed in victory and bought herself dango and red bean soup as her prize.

Uzuki Yugao shook her head slightly, trying to concentrate on the mission at hand. She could ponder on those things later back at the village; to herself of course, Kami forbid what the girls would do if they found out.

"I'm not going to ask again," she murmured, her hot breath softly cascading in waves against her target's ear. Her target shivered.

"He'd kill me..." he pleaded, whimpering under her tight gaze. "Please I have a family-!"

Yugao licked her lips behind her mask slightly.

"Should have thought of that before you gave him the information, now didn't you?" she whispered, voice barely heard yet ominous as the shadows that coated her figure.

The man collapsed, his legs giving out beneath him as he knelt on the ground; his eyes wide and brimming with fear.

"Kusa..." he whispered. "I heard he was in Kusa..."

 _'Mission complete,'_ the purple-haired Anbu member mentally smirked. She clasped her target's face, guiding his eyes to meet hers through the holes on her Neko mask.

"See, was that so hard?" she gently jabbed the kunai into his chest, the metal blade slipping beneath her target's ribcage as warm, wet blood seeped through his gushing wound, staining the man's shirt crimson red. His eyes grew larger in shock, a trickle of blood escaping his lips. The Neko Anbu knelt next to him, whispering softly in his ear in a show of slight pity and mercy.

"Thank you,"

She reached up with one hand, and slowly closed his eyes as the bleeding man keeled over, his breathing shallow as blood dripped from his chin and staining the ground below.

It was slow, yet painless.

"Bury me... burn me..." he coughed out. "So that... he won't find me..."

All the Anbu could do was nod in reluctance. All the man could do in return was nod, smiling slightly before his breathing stilled; Yugao offered a silent prayer for the man's soul even when he was not really deserving of it. It was the humane thing to do.

Yugao felt a hand tap her shoulder.

"Senpai... we should be heading back," Kuma told her softly. "We have what we need."

Yugao nodded, standing back up to her full height; looking into the treeline knowing her teammates were hidden within the shadows of the leaves in the darkness of the night. She wasn't recruited into the Anbu for nothing.

"Bury the body," she ordered calmly, slipping her kunai back into her weapon's pouch. "Leave no traces,"

"Hai taichou! (Yes captain!)" they chorused, her comrades appearing around her, already getting to work in the form of their Shunshins.

Yugao chuckled and with one hand-seal later, she was gone in a swirl of leaves.

* * *

"Mission complete Hokage-sama,"

Hiruzen puffed smoke from his pipe in approval from behind his desk as he looked out beyond the window of the Hokage tower, down on to the village wrapped in the shades of the evening. His gaze froze longingly at one building in particular among the the rest.

"Well done Yuugao; at least now we have a lead..." the elderly Hokage shook his head. "Jiraiya's spy network will be working at full-speed now with this information. You have done this village a great service, I owe you a thank you."

The purple haired woman shook her head. "No thanks is necessary Hokage-sama; I was merely doing my duty."

Hiruzen chuckled. "Even still, grant me this request not as the Hokage but as this old and tired man; I want you to take a break and relax. Work is good and all, but the mind and body needs a steady balance between rest and work."

Yugao spluttered behind her mask. "Hokage-sama, I'm afraid that isn't possible in this situation." she protested. "I have quite a bit of paperwork needed to be filled out back at headquarters, and I still have to file the written mission report-"

"Which I have asked Tenzo to do in your place with the Hokage's approval; and I will ask Okami to write the mission report for you." the Sandaime interrupted her. "You deserve the rest after the amount of stress you've been piling onto your shoulders Yugao..."

The Neko Anbu clenched her fist. "But..."

"No ifs, ands or buts in this case Yugao-chan," Hiruzen sighed, puffing on his pipe slowly. "I'm getting too old for this; I'm just making sure you don't end up doing the same."

As much as she tried, she could simply not look up at the elderly village leader.

"Hai Hokage-sama..."

Sarutobi smiled before a thought dawned on him as he turned around and bent into his drawer, searching through it for something of importance. "Also, I have one last request, consider it your holiday mission; it will be completely off the book."

"Eh? What mission?"

All she got was a folder in response. Gingerly taking it from the Hokage's hand, the purple-haired Anbu quickly leafed through the folder; she browsed the documents and reports located within, her eyes widening with every page turned.

"I know I'm asking a lot from you," Hiruzen admitted, taking his seat facing her with a serious demeanor. "But I wouldn't trust this mission with you if I didn't believe you had the appropriate skills and mind set required for it."

Yugao took of her mask and blinked blankly at the Hokage, who she could tell was smiling with glee behind his serious visage. She knew the habits the old man had developed and his mannerisms all too well with the number of times she was stationed in this office for guard duty.

"Let me get this straight..." she pinched the bridge of her nose before locking eyes with the expectant village leader. "You want me to teach at the Academy...?"

* * *

If you were to enter the classroom of Class A you'd think that it was your run-of-the-mill classroom. That, however, was not the case for this classroom filled with most definitely not ordinary students. Make no mistake, while the students looked regular to the untrained eye; these students were shinobi. And this,

"Hey did you hear that we're getting a new teacher today...?" Fujimori Kenta murmured off-offhandedly.

"Yeah," his fellow student and seatmate Hirata Kyo nodded fervently. "For what though? Iruka-sensei already has our Physical training covered, and Koro-sensei has pretty much everything else."

"Does this mean that they're possibly replacing someone?" Hiroshima Fumiko joined their conversation, voicing her own question on the topic; drawing the attention of most of the class along with it.

"Hey, don't come off like that! There's no way they're getting rid of Iruka-sensei, much less Koro-sensei." Inuzuka Kiba heatedly replied, Akamaru barking his agreement. "They're the best teachers I've ever had; I'm pretty sure everyone here feels the same way."

"Don't get me wrong Kiba," Fumiko immediately shook her head in denial. "I feel the same as you do, but it's not really up to us who gets to teach; and since the council is out of the question, that just leaves Hokage-sama with the decision."

Naruto snorted.

"Yeah right, I've known Jiji for a really long time and I know that's not the way he thinks." Here, the Uzumaki made use of air quotes, imitating the voice of his surrogate grandfather . "'It'd interfere with our training and progress' or something is what he'd most likely say."

Many nodded their shared agreements.

"We do have to take Naruto-kun's opinion into account." Chinatsu said, hand cupped under her chin thoughtfully. "He's known Hokage-sama the longest and the best among us all."

"So... what option does that leave us with? A new subject?" the Inuzuka snorted with mirth. "With our schedule, no way it'd fit! Koro-sensei'd throw a fit if he didn't get enough time to play cat-and-mouse with us."

"I think you mean kill-the-target..." Jirou corrected.

Kiba waved his classmate off. "Tomato-potato, same thing. That reminds me; has anyone come up with any new ways to kill sensei today?"

 _This was their assassination classroom._

Many of them shook their heads in disappointment.

"Not any that would work anyway," Shikamaru commented nonchalantly. "Pretty sure everyone took into account that with how fast sensei can move, his reaction speed coupled with his regeneration factor; it pretty much shuts down a lot of our individual plans from the get-go."

Akimichi Choji blinked. "Shikamaru... that's the longest sentence I've ever heard you speak. And we've been friends for a long time,"

All the chubby boy got as a response from his pineapple-headed friend was a quiet groaned-out "Mendokusai...", earning chuckles from the crowd of students.

"He's right though..." to their shock, Uchiha Sasuke sat next to Aburame Shino and put his two cents in. "Individually, we have no chance at beating sensei."

The Uchiha heir glanced praisingly at the Nara. "Really?"

The Nara groaned once more.

"So what you're saying is..." Naruto cupped his hand under his chin, brows scrunched in concentration. "We have to work together to get him?"

Sasuke nodded, switching his gaze from the Uzumaki to the collective class. "Good work dobe. As much as I hate to admit it; there's no way any of us can take sensei down alone. We have to work together."

"That's rich coming from you,"

"I don't really care much for all this," for emphasis, the Uchiha waved his hand and gestured to the classroom. "But if we want to kill sensei, there's no other way to do it best than to work as a team."

"Correct!"

The class shrieked and jumped back in unison, scrambling about to find lost footing in their panic.

"Sensei?!"

"Nurufufufu..." Koro-sensei laughed, clasping his tentacles together in an approving manner. "You are all correct in your assumptions. Individually, none of you have any chance of hitting, much less killing me. However, together you have a better chance than the entire Anbu force of every village."

"In unity you find strength; and when there is teamwork and collaboration accompanied by enthusiasm and understanding, great things can be achieved among so very few. These are the founding roots in which Konoha and its philosophy of The Will-of-Fire was built upon."

Koro-sensei's face turned a familiar shade of red. "Continue to grow, and I am sure that you will reach your goals. Ones that include killing me I hope," their teacher laughed. "Until then, I will still be your teacher. And so will Iruka-san; I'm sure he's grown quite fond of this class as I have."

Toyoda Nobuyuki shook his head, amused. "The bell hasn't even rung yet and you're already giving a lecture. You sure are something else sensei..." he trailed off.

Koro-sensei simply shook his head and laughed once again.

"An educator never misses an opportunity to teach. A true educator is not simply a person who is there every 8:00 every morning and leaves at the final crack of the bell. We who guide you, and show you the right path and not just tell you where to go."

He then raised once tentacle in a knowing manner. "And if you must know, neither I nor Iruka-san are getting replaced; we are simply getting a new teacher to have lessons alongside Iruka-san during Physical training. In other words, we'll be kicking it up a notch."

"Huh? What do you mean sensei?"

"Nurufufu..." their teacher laughed. "Class, it's about time we truly showed you how to use Chakra."

* * *

"Hello, my name is Uzuki Yugao; I'm here as the assisstant Physical Instructor to Iruka-san. My assignment entails that I give lessons alongside Iruka-san, primarily your Chakra training during the course of your studies., and be the 'model' for the Kunoichi in this class. I hope we can work well together."

The class balked at the purple-haired kunoichi.

They were out on the training field for the physical portion of their education, which was regularly scheduled with Iruka-sensei after two periods with Koro-sensei in the classroom. Once they had arrived, they were greeted by not only their physical instructor, but also by a new face who had been in deep discussion with Iruka before the class accompanied by Koro-sensei had arrived.

"Let me give you the short version: She's here as my assistant to teach you about advanced Chakra techniques. And since Hokage-sama was worried that we would not produce kunoichi that have knowledge in their specific arts since you only have two teachers who are both male; so he decided to kill two birds with one stone and made Yugao here your teacher." Iruka summerized.

"Ano..." Chiasa raised her hand. "Iruka-sensei, I thought you said you'd give us the short version?"

 _'Only you Chiasa...'_ the class sweatdropped in unison.

Iruka blushed slightly and cleared his throat. "A-Anyway, we decided to formally start your training today with one simple exercise; we'll be teaching you to climb trees."

Sakura raised her hand in confusion. "Sensei, we already know how to climb trees; it was taught last year."

All of the students nodded in agreement.

Before Iruka or Yugao could open their mouths to speak, Koro-sensei took the initiative and addressed the class.

"Ah yes, we saw your curriculum last year." he intoned in a knowing manner. "However, can you do it without your hands?"

And to their amazement, Koro-sensei approached one of the many trees that littered the training grounds of the Academy and slowly slithered up a tree trunk laughing all the way at their dumbfound and awed expressions. Iruka coughed to gain their attention again.

"Yes, as your sensei demonstrated, which by the way is our job," Iruka spoke, his eyebrow twitching. "That is the Tree Walking exercise, it is a simple technique which all shinobi can use efficiently. It's basically a must for our line of work."

Yugao nodded. "It allows for a great many things such as infiltration, information gathering, hiding and the field that this class is most likely to specialize in considering your circumstances,"

For emphasis she gave Koro-sensei a sharp look. To his credit, Koro-sensei didn't even bat an eyelash; if he had any at all in the first place.

"Assassination,"

She clapped her hands, smiling joyfully at her now-students. "So... who wants to go first?"

There was a deafening silence that you could hear a pin drop as the class seemed to stand still as if frozen in time. To their trained eyes however, they could pick up the slightest shift in movement and the silent shuffling of feet.

 _'They're worried they might not be able to do it...'_ Iruka realized, and looking over to his colleagues he knew they had come to the same realization. Before he could even speak, Koro-sensei once again spoke.

"All who are able to complete this exercise by today will be exempted from the next History quiz," he cheerfully announced.

Iruka and Yugao would have been trampled over if they were not seasoned shinobi by the hoard of stampeding students who were quickly claiming trees to practice on and began running up the tree trunks only to fall on their backs. The two human teachers sweatdropped.

 _'Is this what a literal assassination classroom is...?'_ Yugao question a bit of her sanity. She heard a chuckle beside her, seeing the scar-nosed Tokubetsu Jonin laugh at the situation at hand. A giggle escaped her lips and she blushed. Iruka glanced at her with a knowing smile, before nodding.

He walked off, approaching the students and began conversing with them as he offered them slight bits of information on how to do the technique.

"You have to focus your chakra to the soles of your feet." The scar-nosed shinobi informed them. "Too little, you fall off. Too much, you get blown off. It's all about finding the right amount of chakra you need."

 _'Maybe this won't be so bad...'_

Out of the corner of her eye, she could see the classroom adviser of the class sitting comfortably on one of the branches of the trees, laughing with a small box of sweets and glass filled with a drink as he watched over their students from above.

Yugao chuckled before walking off to do the same.

Today was a good day for Class A; with many more sure to come.

* * *

 _Kobayashi Atsushi was not a difficult person to describe. He was cunning as he was charismatic and kind, and rightly so. He was born and raised on the aristocratic side of life, living his younger years as a carefree and spoiled child with a good sense of morals of what was right from wrong. He had never let his family's fortune or social standing dissuade his views, so much as to donate half of his share of the family fortune when he reached legal age to the needy._

 _He sponsored many charitable foundations and liked to spend time with his family in the comforts of his two-storey house, even inviting the homeless in during the holidays and allowing them room until they saw fit. He always made sure his help composed of two maids would attend to their needs and make them feel welcome in his home. He was a veritable saint; people praised him, and loved him._

 _Life was good._

 _Before he went to bed, he payed a visit to his children's shared bedroom like he did every night; telling them a story before tucking them into bed for the night until the sun woke the sky the following day._

 _"Oyasuminasai (Good night)..." he whispered, kissing his children's foreheads with a tender touch, to his children's incessant giggles. By the time he had looked again, his children had already fallen into sleep's calming embrace. He chuckled, quietly stepping out of the bedroom; closing the door behind him._

 _He slid underneath the covers upon arriving at his bedroom, making sure to snake his arms around his loving wife to her surprise. He snuggled in, his nose on her hair breathing in her strawberry-cinnamon scent._

 _"Have I ever told you how much I love you?" he murmured against her neck, causing a pleasant shiver running through his most beloved's spine._

 _"Enough that I'd be as rich as you," his wife Arisu retorted teasingly, flipping over to face her husband; running her slender fingers on his chiseled face. "Even then I'd still have change,"_

 _"Then I'm all the happier to make you richer," he replied earnestly, grasping her hand and kissing it gently._

 _Arisu giggled slightly, softly grasping her husband's hand; guiding it to her bare stomach. "You already have," she whispered gently, caressing her flat abdomen gently; her voice soft and mellifluous to his graced ears._

 _His eyes widened as he gaped to his still smiling wife._

 _"Y-You mean...?" he pointed to her stomach blankly, to the deadpan and amused stare of his wife. "I-I'm gonna... again...?"_

 _Arisu giggled into her hand. "Look at it this way; this time it's not twins so we can share diaper duty."_

 _Atsushi breathed a sigh of praise and relief, once again to the bemused reaction of his wife. "Thank Kami-sama...!"_

 _The overjoyed man quickly rose from his bed, whopping with great joy with his wife laughing at him. He rushed downstairs, proclaiming that it was a cause for celebration and dashed to the kitchen, fetching a glass of wine proclaiming to the help the joyous news while doing so._

 _When he reached their bedroom again, no longer was his wife in their bed. He frantically looked around, before spotting the door to the balcony ajar. He walked to the balcony, his wife leaning against the railing under the light of the moon under the night sky._

 _He placed the bottle down on a table on the balcony before wrapping his arms around his wife's waist, burying his face in the crook of her neck._

 _"I love you..."_

 _He could hear her giggle, before unwrapping his arms around her and quickly grabbing the bottle from the table, taking two small glass from the same table and pouring some in both before handing one to her husband._

 _He smiled and took the glass, raising it in the air as a toast in celebration._

 _"A toast; to life and love." His wife giggled but nodded nonetheless. He chuckled and brought the glass to his lips._

 _And then pain. He could feel a violent slash go against his unprotected throat, as he began to choke on his quickly spilling blood; his hand falling limp and the sound of shattering glass was heard. He could vaguely hear his wife suddenly scream in panic, before a dark figure quickly rushed her, before suddenly appearing standing on the railing with a small glass filled with wine already raised to his lip._

 _Atsushi's eyes widened in horror as he could do nothing as helplessly watch his wife's stricken look, blood across her neck before it gave way and her head was completely severed from her body._

 _All he saw before darkness overtook his vision was a pair of cyan-colored eyes gaze at him lifelessly and their owner speaking one word._

 _"Weak..."_

 _And then nothingness._

* * *

"By the way, Kiba-san..."

"Yeah?"

"A tomato isn't a potato. I'd just like to clear that up."

"..."

* * *

 **And there we go! Chapter 6 of Unkillable finished and done! Please leave a review, comment or critique! Just for this Christmas!**

 **Anyway, I hope you all enjoyed. Again, Merry Christmas and a Happy New Year to you all! This is Sensei, signing off!**


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